Rock drill



Patented July 7, 1925.

UNITED STATES Pulsar carica.l

LEWIS C. BAYLES, F EASTON, PENNSYLVANIA, ASSIGNOR T0 INGERSOLIr-RAND COM- PANY, 0F JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ROCK DRILL.

Application leil July 22, 1924. Serial No. 727,414.

To all whom it may concern):

- Be it known that I, LEWIS C. BAYLES, a

citizen of the United States, and a resident of Easton, county of Northampton, State of Pennsylvania, have invented a certain Rock Drill, of which the following is a specication, accompanied by drawings.

This invention -relates to `rock drills and provides features which are of general applie-ation thereto, being more particularly adapted for use in that type of drill provided with means for supplying water into the center bore of the drill steel for cleansing the hole to be bored. Certain features l5 of the invention may, however, be applied to rock drills adapted to bore dry holes.

In rock drills one of the least durable parts is the front head. This is due to the fact that the shank of thesteel reciprocates in the chuck which is part of the front head and also binds due to the turning caused by the rotation mechanism or manual rotation of the drill. Wear in these parts is aggravated by mud in the case of wet drilling l or dust in the dry drilling which finds its way into the chuck or other front head parts from the exterior. Also, in that type of rock drill commonly known as stopers which are adapted to drill upwardly with the drill in a vertical position, cleansing water is apt to collect in the front parts of the drill ahead of the anvil block adapted to trans-I mit the hammer blow to the steel. Water accumulates in the front part of the drill partlyby leakage from the supply in the tool, and partly by leakage of water flowing down the steel from the hole being drilled. Water collectingin this manner produces water hammer 'and prevents 40 freedom of motion in the front part of the tool and also absorbs part of the force of theblow delivered to the steel.

One of the ob'ects of the invention is to reduce the wear tween the front head and the drill steel. Another object of the invention is to revent leakage from the water supply into t e tool and also to prevent the accumulation of water entering from the exterior. 1 l

The invention will be more clearlyr understood by reference to the following 'description and the accompanying drawings, in which- Figure 1 is a longitudinal sectional view of the forward part of a drill showing the means for supplying water to the hollow bore of the steel and the means by which leakage therefrom is prevented,

Figure 2 is a longitudinal section of the forward part of a drill taken along the lines @0 2-2 looking in the direction of the arrows and shows more particularly the means by whlch the accumulation of water leaking into the drill from the exterior is prevented, l and l 65 Figure 3 is a cross sectional view taken along the lines 3 3 looking in the direction of the arrows.

Referring to the drawings, only s'o much of a rock drill is shown as is pertinent to the invention. The rock drill comprises a cylinder A of any suitable type in which there is adapted to reciprocate a hammer piston B for delivering rapidly repeated blows to an anvil block C in contact with a drill steel D. The drawing illustrates the forward part of a drill commonly termed a stoper which is adapted to drill holes upwardly. In this type of drill an anvil block is usually employed to seal the forward end of the 8 cylinder against leakage of water which would wash the lubrication and otherwise interfere with the proper operation of the tool. The rotation of the steel .D in'this drill may be accomplished by rotating the entire drill by a suitable handle (not shown) extending laterally therefrom.

In order to support the anvil block C there is provided an anvil block seat E which together with the anvil block C closes .90 the forward end of the cylinder A. At the forward end of. the anvil block seat E there is mounted a front head F provided with internal flutes H on the chuck J for holding the steel D. The anvil block seat E and the 95 front head F are attached to the cylinder A by means of front head bolts K provided with springs L to absorb vibration and shock when the piston B strikes the anvil block seat E.

It is desirable that the anvil block be held against rotation with respect to the cylinder A and to this end the aperture O in the anvil block seat E through which the anvil block extends into the cylinder A is not cylindrical preferably having two flat sides to correspond with the flat sides P on the end of the anvil/,.block. The seat E is recessed as by a cylindrical bore Q to permit the cylindrical head R of the anvil block to move longitudinally a slight amount when struck by the hammer piston B.

To admit cleansing water to the hollow steel, means are provided including a passage-way S extending longitudinally of the cylinder A and connecting with a longitudinal passage T in the anvil block seat E to connect With a assage U in the anvil block C leading to t e bore of the steel D. In order to prevent leakage of water between the head R of the anvil block and the bore Q of the seat E there is provided a short tube V connecting with the passage T and adapted to bear against the cylindrical surface of the head R under tension of a coil spring W held in place by a plug X in the anvil block seat E.

In order to keep the chuck J from being removed accidently from the front head F there is provided a head Y which may be integral with the chuck J and which has an outer surface to correspond with the recess or bore Q. It is desirable to prevent substantial leakage of cleansing water from the passage U past the chuck J and out through the front head F partly because if there be such leakage the greater part of the cleansing water will escape because the vertical position 'of the drill and' steel D produces a considerable back pressure especially if the steel D is of considerable length, and

- partly because, if such water is permitted to collect in the bore Q forwardly of the head.

Y of the chuck J as at Z, a large part of theforce delivered by the piston B to the anvil block C- is transmitted through this water in the recess Z directly `to the front head F land is absorbed without doing eii'ective work on the steel D. Means are provided to prel vent such leaka e which includes a cylindrical extension on the head R of the anvil block C which is adated to cooperate with a bore c in the head of the chuck J. There is preferably a relatively tight fit between the bore c and the cylindrical extension b which prevents any substantial escape of water between the anvil block and the chuck. l

It is impractical to make the parts t so tightly that no Water will escape and therefore means are provided to remove the wa'- ter accumulating in the recess Z and thereby eliminating the water hammer. To this end a passage al communicating with the recess Z is provided extending through the anvil block seat E. This passage d may communicate by means of a passage e extending longitudinally in the wall of the cylinder A to provide air under pressureto b ow the accumulating water out along the flutes H of the chuck J. This is preferable since it maintains the chuck J reeof mud and dirty water which -is apt to find its way down past the utes H into the recess Z.

seen that the steel D and the chuck J arev substantially stationary with respect to each other and therefore little or no wear `will occur between the flat sides of the shank of the steel and the interior of the chuck. The chuck J and the drill steel D move as a unit in the front head F. A relatively large bearing area Ibetween the chuck J and the front head F is provided with the flutes H and since the flutes may be formed so as to fit with relatively little clearance in the front head F, these parts will be very durable. The drill steelD and the chuckJ may be held together more securely by an air -cushion produced by air under pressure admitted through the passage d into the recessy Z thereby ,holding the chuck J firmly down on the anvil block seat E. vl`he drill steel D will correspondingly be held down against the cylindrical extension b of the anvil block C'. Whether the drilling be dry or wet the air leaking from the recess Z along the flutes H will keep out mud or dust. Additionally, if the air supplied for operating the tool is prepared by means of an air line oiler or similar well known device, oil will be carried into the recess Z and to the flutes H to provide constant lubrication.

I claim:

1. A rock drill comprising a cylinder, a front head, an anvil block, a chuck longitudinally slidable in said front head adapted to receive a drill steel, and means to hold said chuck against said anvil block.

2. A rock drill comprising a cylinder, a front head, an anvil block, a chuck longitudinally slidable in said front head adapted to receive a drill steel, and means to hold said chuck against said anvil block including air cushioning means. y

3. A rock drill comprising a cylinder, an anvil block, an anvil block seat attached to the cylinder, means to admit cleansing water through said anvil block into a hollow drill steel, and a chuck for a drill steel cooperal5" to a hollow steel, a chuc extending through;

the cylinder, a front head rovided with internal flutes, a chuck ilute to coo erate' steel :in the chuck, means to prevent leakage of such cleansing water between said chuck andl said anvil block including a head on the chuck, and means to remove water. accumulated forwardly of the head of said chuck..

6. A rock drill comprising a cylinder, an anvil block, an anvil block seat attached to the cylinder, a front head, means to admit cleansing water throu h said anvil block said front head and into the anvil block seat, means to prevent leakage of said water between the anvil block and the chuck including a/cylindrical extension on the anvil block and a head on the chuck provided with a bore cooperative with said cylindrical extension, and means to remove water ac cumulated forwardly of the head of said chuck.

7. A. rock drill com rising a cylinder, an anvil block, an anvil lock seat attached to the cylinder, a front head, means to admit cleansing water through said anvil block to a hollow steel, a chuck extending through l said front head and into the anvil block seat, means to prevent leaka e of said water between the anvil block an the chuck including a cylindrical extension on the anvil block and a head on the chuck provided` with a bore cooperative with said cylindrical extension, and means to remove water accumulated forwardly of the head of-said chuck including a passagewa for pressure iiuid extending through sai anvil block seat.

8. A rock drill comprising a cylinder, an anvil blockI seat attached to the c linder having a bore in alignment with sai cylinder and an apertureextending into the cylinder, an anvil block extendin through said aperture into the cylinder and aving a head fitting the bore of said seat and provided with a cylindrical extension adapted to connect with a hollow drill steel, a front head internally iluted, a chuck luted to cooperate with said front head having ahead slidable in the bore of said anvil block-seat and bored to t tightly the cylindrical extension on said anv1l block, means to admit cleansing water through the anvil block into said hollo'w drill steel, and means to remove accumulated water from said anvil block seat beyond the head of the chuck including a passageway for pressure fluid leading from the bore of said seat through said seat.

In testimony whereof I have signed this specification.

LEWIS c. BAYLES. 

